It is well known to bond a precured rubber tread strip to a tire periphery with a rubber based bonding medium which vulcanizes when heat and pressure are applied to the assembly of tire and tread strip. It is also known, as disclosed in U.S. Pat. No. 3,884,739, to retread a plurality of enveloped tires by stacking them vertically on a base with plate elements disposed between the individual tires, placing the assembly of stacked tires in an autoclave and effecting seals between the precured tread within the envelopes and their respective tires by inflating the tires themselves so as to compress the stack between the base and a fixed element in the autoclave. A stack of such tires with alternate planar support means disposed between each of the tires in the stack placed in the autoclave, are shown in my copending application Ser. No. 724,766 filed Sept. 20, 1976 for Retreading Stacked Tires.